Americans typically want more spending on defense but favor cutting back when they are told how much actually is spent on defense compared to other budget items, according to opinion data released Thursday.

Three-quarters of Americans said they supported cutting defense to reduce the federal budget deficit, according to the survey, published by the Program for Public Consultation at the University of Maryland.

That majority is bipartisan: About 67 percent of Republicans and 90 percent of Democrats supported cutting the defense budget, the survey data show.

On average, those surveyed advocated an 18 percent cut from the current fiscal 2012 budget levels. Republicans wanted an average of a 12 percent cut and Democrats 22 percent.

Those surveyed were given figures about the size of the current defense budget compared with other budget items and historic defense spending levels, “and presented with arguments that experts make for and against cuts,” according to the researchers.

Most respondents said defense spending was more than they had expected when compared to other items in the discretionary budget (65 percent), to historical defense spending levels adjusted for inflation (60 percent), and to the defense spending of U.S. allies and potential enemies (56 percent).

“This suggests that Americans generally underestimate the size of the defense budget and that when they receive balanced information about its size they are more likely to [want to] cut it to reduce the deficit,” said Steven Kull, the center’s director.

The study was conducted April 12-18 using a sample of 665 American adults, and has a margin of error of plus-or-minus 4.8 percentage points.